This research will seek to delineate the biochemical mechanisms in ocular epithelial tissues by which the intracellular concentrations of cyclic 3',5'-AMP (c-AMP) and cyclic 3',5'-GMP (c-GMP) are regulated in relation to PG synthesis. These investigations will use, primarily, isolated cell types obtaind by enzymatic digestion followed by density gradient centrifugation. These types of rabbit epithelial tissues will be examined: Those associated with a rich blood supply (pigmented and nonpigmented epithelial cells from ciliary process tissues, pigmented epithelial cells from the retina, eipthelial cells from choroid plexus of the brain and isolated collecting tubules from the kidney cortex); those with no vascular association (endothelial and epithelial cells from the cornea); and those without blood supply or innervation (lens epithelial cells). Studies will continue using isolated cells prelabeled simultaneously with C14-adenine, (C14)-hypoxanthine and (C14)-dihomo-gamma-linolenic acid with subsequent isolation and counting of synthesized (C14)-c-AMP, (C14)-c-GMP and (C14)-prostaglandins (PGs) along with tracer (H3)-c-AMP, (H3)-c-GMP and (H3)-PGs for recovery correction. Effects of added cyclic nucleotides or PGs upon endogenous levels will be examined as well as adrenergic and cholinergic drugs. Interesting observations will be backed up by adenylate cyclase and c-AMP phosphodiesterase assays. Some ocular epithelial tissues of rabbits with hereditary buphthalmia will also be examined.